President Reagan sounded a possible 1984 campaign theme tonight, arguing that the nation is better off than it was nearly four years ago, particularly in its foreign policy, and rejecting charges that his domestic policies have been unfair to the poor.

Reagan, in South Carolina campaigning for Sen. Strom Thurmond (R-S.C.), who is running for his sixth term, appeared to be campaigning as much for himself. He repeatedly countered Democratic critics by saying, "Some people don't seem to like anything we do."

He took the offensive on his foreign policy, contending that the United States no longer needs to engage in "hand-wringing and apologizing." He said that his administration has brought a "new sense of purpose and direction to America's foreign policy."

The president dismissed charges that he is unfair to the poor with a slap at the Democrats, accusing them of really "complaining that all their special interests have been hurt."

He criticized "liberals" who oppose his tax cuts, and "misery merchants," who he said "whine, carp and complain," instead of getting out of the way of the economic recovery that is the result of his policies.

Reagan also returned to a 1980 campaign theme by attacking Washington, D.C., and big government. He said common sense in Washington is as common as "a Fourth of July blizzard in Columbia, S.C."

He answered Democratic attempts to make fairness to the poor an issue in the 1984 election by saying, "Big spenders who saddled America with double-digit inflation . . . and phony excuses about malaise are the last people who should give sermonettes on fairness and compassion."

Instead, Reagan depicted his administration as one that came to the capital four years ago "to save a nation whose house was on fire. We put out the fire, and brick by brick we're rebuilding. . . . "

One adviser traveling with Reagan said the speech had some "feelers in it for the campaign trail" if Reagan decides to run.

"If they want to say we're unfair or ask people if they were better off under our administration or the previous four years of Jimmy Carter, we'll be happy to tackle that," the adviser said.

Reagan, speaking here at the South Carolina fairgrounds, compared his administration with Carter's.

"I believe with all my heart that the U.S. is safer, stronger and more secure today--both economically and militarily--than before . . . , " Reagan said. "I believe one word sums up the difference between today and 1980: hope. Hope is being reborn in America . . . .

"Too many of our opponents are only comfortable trusting government. Their solution--higher taxes and spending--would bring us back full circle to the source of our economic problems . . . .Our road is bold and filled with hope. Their road is timid and appeals to fear and envy."

The president also defended his foreign policy decisions after referring to the Soviet destruction of the Korean Air Lines airliner.

"We live in a dangerous world with people who reject our ideals," he said.

"In foreign policy we've let the world know that America stands up for democratic ideals again. . . . America doesn't put up walls to keep her people in, we don't use an army of secret police to keep them quiet, we don't imprison political and religious dissidents in mental hospitals and we don't cold-bloodedly shoot defenseless airliners out of the sky."

Reagan made only a brief reference to the compromise with Congress on the War Powers Resolution today, saying that it signals "bipartisan cooperation, especially in foreign policy where politics should stop at the water's edge."

Earlier in the day at the University of South Carolina, where he received an honorary doctor of laws degree, Reagan resurrected his past advocacy of tuition tax credits and a constitutional amendment allowing prayer in schools, and defended merit pay for public school teachers.